1 // SPDX-License-Identifier: GPL-2.0
3 * CPUFreq governor based on scheduler-provided CPU utilization data.
5 * Copyright (C) 2016, Intel Corporation
6 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/sched/cpufreq.h>
14 #include <trace/events/power.h>
16 #define IOWAIT_BOOST_MIN (SCHED_CAPACITY_SCALE / 8)
18 struct sugov_tunables
{
19 struct gov_attr_set attr_set
;
20 unsigned int rate_limit_us
;
24 struct cpufreq_policy
*policy
;
26 struct sugov_tunables
*tunables
;
27 struct list_head tunables_hook
;
29 raw_spinlock_t update_lock
; /* For shared policies */
30 u64 last_freq_update_time
;
31 s64 freq_update_delay_ns
;
32 unsigned int next_freq
;
33 unsigned int cached_raw_freq
;
35 /* The next fields are only needed if fast switch cannot be used: */
36 struct irq_work irq_work
;
37 struct kthread_work work
;
38 struct mutex work_lock
;
39 struct kthread_worker worker
;
40 struct task_struct
*thread
;
41 bool work_in_progress
;
44 bool need_freq_update
;
48 struct update_util_data update_util
;
49 struct sugov_policy
*sg_policy
;
52 bool iowait_boost_pending
;
53 unsigned int iowait_boost
;
59 /* The field below is for single-CPU policies only: */
60 #ifdef CONFIG_NO_HZ_COMMON
61 unsigned long saved_idle_calls
;
65 static DEFINE_PER_CPU(struct sugov_cpu
, sugov_cpu
);
67 /************************ Governor internals ***********************/
69 static bool sugov_should_update_freq(struct sugov_policy
*sg_policy
, u64 time
)
74 * Since cpufreq_update_util() is called with rq->lock held for
75 * the @target_cpu, our per-CPU data is fully serialized.
77 * However, drivers cannot in general deal with cross-CPU
78 * requests, so while get_next_freq() will work, our
79 * sugov_update_commit() call may not for the fast switching platforms.
81 * Hence stop here for remote requests if they aren't supported
82 * by the hardware, as calculating the frequency is pointless if
83 * we cannot in fact act on it.
85 * For the slow switching platforms, the kthread is always scheduled on
86 * the right set of CPUs and any CPU can find the next frequency and
87 * schedule the kthread.
89 if (sg_policy
->policy
->fast_switch_enabled
&&
90 !cpufreq_this_cpu_can_update(sg_policy
->policy
))
93 if (unlikely(sg_policy
->limits_changed
)) {
94 sg_policy
->limits_changed
= false;
95 sg_policy
->need_freq_update
= true;
99 delta_ns
= time
- sg_policy
->last_freq_update_time
;
101 return delta_ns
>= sg_policy
->freq_update_delay_ns
;
104 static bool sugov_update_next_freq(struct sugov_policy
*sg_policy
, u64 time
,
105 unsigned int next_freq
)
107 if (sg_policy
->next_freq
== next_freq
)
110 sg_policy
->next_freq
= next_freq
;
111 sg_policy
->last_freq_update_time
= time
;
116 static void sugov_fast_switch(struct sugov_policy
*sg_policy
, u64 time
,
117 unsigned int next_freq
)
119 struct cpufreq_policy
*policy
= sg_policy
->policy
;
122 if (!sugov_update_next_freq(sg_policy
, time
, next_freq
))
125 next_freq
= cpufreq_driver_fast_switch(policy
, next_freq
);
129 policy
->cur
= next_freq
;
131 if (trace_cpu_frequency_enabled()) {
132 for_each_cpu(cpu
, policy
->cpus
)
133 trace_cpu_frequency(next_freq
, cpu
);
137 static void sugov_deferred_update(struct sugov_policy
*sg_policy
, u64 time
,
138 unsigned int next_freq
)
140 if (!sugov_update_next_freq(sg_policy
, time
, next_freq
))
143 if (!sg_policy
->work_in_progress
) {
144 sg_policy
->work_in_progress
= true;
145 irq_work_queue(&sg_policy
->irq_work
);
150 * get_next_freq - Compute a new frequency for a given cpufreq policy.
151 * @sg_policy: schedutil policy object to compute the new frequency for.
152 * @util: Current CPU utilization.
153 * @max: CPU capacity.
155 * If the utilization is frequency-invariant, choose the new frequency to be
156 * proportional to it, that is
158 * next_freq = C * max_freq * util / max
160 * Otherwise, approximate the would-be frequency-invariant utilization by
161 * util_raw * (curr_freq / max_freq) which leads to
163 * next_freq = C * curr_freq * util_raw / max
165 * Take C = 1.25 for the frequency tipping point at (util / max) = 0.8.
167 * The lowest driver-supported frequency which is equal or greater than the raw
168 * next_freq (as calculated above) is returned, subject to policy min/max and
169 * cpufreq driver limitations.
171 static unsigned int get_next_freq(struct sugov_policy
*sg_policy
,
172 unsigned long util
, unsigned long max
)
174 struct cpufreq_policy
*policy
= sg_policy
->policy
;
175 unsigned int freq
= arch_scale_freq_invariant() ?
176 policy
->cpuinfo
.max_freq
: policy
->cur
;
178 freq
= map_util_freq(util
, freq
, max
);
180 if (freq
== sg_policy
->cached_raw_freq
&& !sg_policy
->need_freq_update
)
181 return sg_policy
->next_freq
;
183 sg_policy
->need_freq_update
= false;
184 sg_policy
->cached_raw_freq
= freq
;
185 return cpufreq_driver_resolve_freq(policy
, freq
);
189 * This function computes an effective utilization for the given CPU, to be
190 * used for frequency selection given the linear relation: f = u * f_max.
192 * The scheduler tracks the following metrics:
194 * cpu_util_{cfs,rt,dl,irq}()
197 * Where the cfs,rt and dl util numbers are tracked with the same metric and
198 * synchronized windows and are thus directly comparable.
200 * The cfs,rt,dl utilization are the running times measured with rq->clock_task
201 * which excludes things like IRQ and steal-time. These latter are then accrued
202 * in the irq utilization.
204 * The DL bandwidth number otoh is not a measured metric but a value computed
205 * based on the task model parameters and gives the minimal utilization
206 * required to meet deadlines.
208 unsigned long schedutil_cpu_util(int cpu
, unsigned long util_cfs
,
209 unsigned long max
, enum schedutil_type type
,
210 struct task_struct
*p
)
212 unsigned long dl_util
, util
, irq
;
213 struct rq
*rq
= cpu_rq(cpu
);
215 if (!IS_BUILTIN(CONFIG_UCLAMP_TASK
) &&
216 type
== FREQUENCY_UTIL
&& rt_rq_is_runnable(&rq
->rt
)) {
221 * Early check to see if IRQ/steal time saturates the CPU, can be
222 * because of inaccuracies in how we track these -- see
223 * update_irq_load_avg().
225 irq
= cpu_util_irq(rq
);
226 if (unlikely(irq
>= max
))
230 * Because the time spend on RT/DL tasks is visible as 'lost' time to
231 * CFS tasks and we use the same metric to track the effective
232 * utilization (PELT windows are synchronized) we can directly add them
233 * to obtain the CPU's actual utilization.
235 * CFS and RT utilization can be boosted or capped, depending on
236 * utilization clamp constraints requested by currently RUNNABLE
238 * When there are no CFS RUNNABLE tasks, clamps are released and
239 * frequency will be gracefully reduced with the utilization decay.
241 util
= util_cfs
+ cpu_util_rt(rq
);
242 if (type
== FREQUENCY_UTIL
)
243 util
= uclamp_util_with(rq
, util
, p
);
245 dl_util
= cpu_util_dl(rq
);
248 * For frequency selection we do not make cpu_util_dl() a permanent part
249 * of this sum because we want to use cpu_bw_dl() later on, but we need
250 * to check if the CFS+RT+DL sum is saturated (ie. no idle time) such
251 * that we select f_max when there is no idle time.
253 * NOTE: numerical errors or stop class might cause us to not quite hit
254 * saturation when we should -- something for later.
256 if (util
+ dl_util
>= max
)
260 * OTOH, for energy computation we need the estimated running time, so
261 * include util_dl and ignore dl_bw.
263 if (type
== ENERGY_UTIL
)
267 * There is still idle time; further improve the number by using the
268 * irq metric. Because IRQ/steal time is hidden from the task clock we
269 * need to scale the task numbers:
272 * U' = irq + --------- * U
275 util
= scale_irq_capacity(util
, irq
, max
);
279 * Bandwidth required by DEADLINE must always be granted while, for
280 * FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism
281 * to gracefully reduce the frequency when no tasks show up for longer
284 * Ideally we would like to set bw_dl as min/guaranteed freq and util +
285 * bw_dl as requested freq. However, cpufreq is not yet ready for such
286 * an interface. So, we only do the latter for now.
288 if (type
== FREQUENCY_UTIL
)
289 util
+= cpu_bw_dl(rq
);
291 return min(max
, util
);
294 static unsigned long sugov_get_util(struct sugov_cpu
*sg_cpu
)
296 struct rq
*rq
= cpu_rq(sg_cpu
->cpu
);
297 unsigned long util
= cpu_util_cfs(rq
);
298 unsigned long max
= arch_scale_cpu_capacity(sg_cpu
->cpu
);
301 sg_cpu
->bw_dl
= cpu_bw_dl(rq
);
303 return schedutil_cpu_util(sg_cpu
->cpu
, util
, max
, FREQUENCY_UTIL
, NULL
);
307 * sugov_iowait_reset() - Reset the IO boost status of a CPU.
308 * @sg_cpu: the sugov data for the CPU to boost
309 * @time: the update time from the caller
310 * @set_iowait_boost: true if an IO boost has been requested
312 * The IO wait boost of a task is disabled after a tick since the last update
313 * of a CPU. If a new IO wait boost is requested after more then a tick, then
314 * we enable the boost starting from IOWAIT_BOOST_MIN, which improves energy
315 * efficiency by ignoring sporadic wakeups from IO.
317 static bool sugov_iowait_reset(struct sugov_cpu
*sg_cpu
, u64 time
,
318 bool set_iowait_boost
)
320 s64 delta_ns
= time
- sg_cpu
->last_update
;
322 /* Reset boost only if a tick has elapsed since last request */
323 if (delta_ns
<= TICK_NSEC
)
326 sg_cpu
->iowait_boost
= set_iowait_boost
? IOWAIT_BOOST_MIN
: 0;
327 sg_cpu
->iowait_boost_pending
= set_iowait_boost
;
333 * sugov_iowait_boost() - Updates the IO boost status of a CPU.
334 * @sg_cpu: the sugov data for the CPU to boost
335 * @time: the update time from the caller
336 * @flags: SCHED_CPUFREQ_IOWAIT if the task is waking up after an IO wait
338 * Each time a task wakes up after an IO operation, the CPU utilization can be
339 * boosted to a certain utilization which doubles at each "frequent and
340 * successive" wakeup from IO, ranging from IOWAIT_BOOST_MIN to the utilization
341 * of the maximum OPP.
343 * To keep doubling, an IO boost has to be requested at least once per tick,
344 * otherwise we restart from the utilization of the minimum OPP.
346 static void sugov_iowait_boost(struct sugov_cpu
*sg_cpu
, u64 time
,
349 bool set_iowait_boost
= flags
& SCHED_CPUFREQ_IOWAIT
;
351 /* Reset boost if the CPU appears to have been idle enough */
352 if (sg_cpu
->iowait_boost
&&
353 sugov_iowait_reset(sg_cpu
, time
, set_iowait_boost
))
356 /* Boost only tasks waking up after IO */
357 if (!set_iowait_boost
)
360 /* Ensure boost doubles only one time at each request */
361 if (sg_cpu
->iowait_boost_pending
)
363 sg_cpu
->iowait_boost_pending
= true;
365 /* Double the boost at each request */
366 if (sg_cpu
->iowait_boost
) {
367 sg_cpu
->iowait_boost
=
368 min_t(unsigned int, sg_cpu
->iowait_boost
<< 1, SCHED_CAPACITY_SCALE
);
372 /* First wakeup after IO: start with minimum boost */
373 sg_cpu
->iowait_boost
= IOWAIT_BOOST_MIN
;
377 * sugov_iowait_apply() - Apply the IO boost to a CPU.
378 * @sg_cpu: the sugov data for the cpu to boost
379 * @time: the update time from the caller
380 * @util: the utilization to (eventually) boost
381 * @max: the maximum value the utilization can be boosted to
383 * A CPU running a task which woken up after an IO operation can have its
384 * utilization boosted to speed up the completion of those IO operations.
385 * The IO boost value is increased each time a task wakes up from IO, in
386 * sugov_iowait_apply(), and it's instead decreased by this function,
387 * each time an increase has not been requested (!iowait_boost_pending).
389 * A CPU which also appears to have been idle for at least one tick has also
390 * its IO boost utilization reset.
392 * This mechanism is designed to boost high frequently IO waiting tasks, while
393 * being more conservative on tasks which does sporadic IO operations.
395 static unsigned long sugov_iowait_apply(struct sugov_cpu
*sg_cpu
, u64 time
,
396 unsigned long util
, unsigned long max
)
400 /* No boost currently required */
401 if (!sg_cpu
->iowait_boost
)
404 /* Reset boost if the CPU appears to have been idle enough */
405 if (sugov_iowait_reset(sg_cpu
, time
, false))
408 if (!sg_cpu
->iowait_boost_pending
) {
410 * No boost pending; reduce the boost value.
412 sg_cpu
->iowait_boost
>>= 1;
413 if (sg_cpu
->iowait_boost
< IOWAIT_BOOST_MIN
) {
414 sg_cpu
->iowait_boost
= 0;
419 sg_cpu
->iowait_boost_pending
= false;
422 * @util is already in capacity scale; convert iowait_boost
423 * into the same scale so we can compare.
425 boost
= (sg_cpu
->iowait_boost
* max
) >> SCHED_CAPACITY_SHIFT
;
426 return max(boost
, util
);
429 #ifdef CONFIG_NO_HZ_COMMON
430 static bool sugov_cpu_is_busy(struct sugov_cpu
*sg_cpu
)
432 unsigned long idle_calls
= tick_nohz_get_idle_calls_cpu(sg_cpu
->cpu
);
433 bool ret
= idle_calls
== sg_cpu
->saved_idle_calls
;
435 sg_cpu
->saved_idle_calls
= idle_calls
;
439 static inline bool sugov_cpu_is_busy(struct sugov_cpu
*sg_cpu
) { return false; }
440 #endif /* CONFIG_NO_HZ_COMMON */
443 * Make sugov_should_update_freq() ignore the rate limit when DL
444 * has increased the utilization.
446 static inline void ignore_dl_rate_limit(struct sugov_cpu
*sg_cpu
, struct sugov_policy
*sg_policy
)
448 if (cpu_bw_dl(cpu_rq(sg_cpu
->cpu
)) > sg_cpu
->bw_dl
)
449 sg_policy
->limits_changed
= true;
452 static void sugov_update_single(struct update_util_data
*hook
, u64 time
,
455 struct sugov_cpu
*sg_cpu
= container_of(hook
, struct sugov_cpu
, update_util
);
456 struct sugov_policy
*sg_policy
= sg_cpu
->sg_policy
;
457 unsigned long util
, max
;
461 sugov_iowait_boost(sg_cpu
, time
, flags
);
462 sg_cpu
->last_update
= time
;
464 ignore_dl_rate_limit(sg_cpu
, sg_policy
);
466 if (!sugov_should_update_freq(sg_policy
, time
))
469 /* Limits may have changed, don't skip frequency update */
470 busy
= !sg_policy
->need_freq_update
&& sugov_cpu_is_busy(sg_cpu
);
472 util
= sugov_get_util(sg_cpu
);
474 util
= sugov_iowait_apply(sg_cpu
, time
, util
, max
);
475 next_f
= get_next_freq(sg_policy
, util
, max
);
477 * Do not reduce the frequency if the CPU has not been idle
478 * recently, as the reduction is likely to be premature then.
480 if (busy
&& next_f
< sg_policy
->next_freq
) {
481 next_f
= sg_policy
->next_freq
;
483 /* Reset cached freq as next_freq has changed */
484 sg_policy
->cached_raw_freq
= 0;
488 * This code runs under rq->lock for the target CPU, so it won't run
489 * concurrently on two different CPUs for the same target and it is not
490 * necessary to acquire the lock in the fast switch case.
492 if (sg_policy
->policy
->fast_switch_enabled
) {
493 sugov_fast_switch(sg_policy
, time
, next_f
);
495 raw_spin_lock(&sg_policy
->update_lock
);
496 sugov_deferred_update(sg_policy
, time
, next_f
);
497 raw_spin_unlock(&sg_policy
->update_lock
);
501 static unsigned int sugov_next_freq_shared(struct sugov_cpu
*sg_cpu
, u64 time
)
503 struct sugov_policy
*sg_policy
= sg_cpu
->sg_policy
;
504 struct cpufreq_policy
*policy
= sg_policy
->policy
;
505 unsigned long util
= 0, max
= 1;
508 for_each_cpu(j
, policy
->cpus
) {
509 struct sugov_cpu
*j_sg_cpu
= &per_cpu(sugov_cpu
, j
);
510 unsigned long j_util
, j_max
;
512 j_util
= sugov_get_util(j_sg_cpu
);
513 j_max
= j_sg_cpu
->max
;
514 j_util
= sugov_iowait_apply(j_sg_cpu
, time
, j_util
, j_max
);
516 if (j_util
* max
> j_max
* util
) {
522 return get_next_freq(sg_policy
, util
, max
);
526 sugov_update_shared(struct update_util_data
*hook
, u64 time
, unsigned int flags
)
528 struct sugov_cpu
*sg_cpu
= container_of(hook
, struct sugov_cpu
, update_util
);
529 struct sugov_policy
*sg_policy
= sg_cpu
->sg_policy
;
532 raw_spin_lock(&sg_policy
->update_lock
);
534 sugov_iowait_boost(sg_cpu
, time
, flags
);
535 sg_cpu
->last_update
= time
;
537 ignore_dl_rate_limit(sg_cpu
, sg_policy
);
539 if (sugov_should_update_freq(sg_policy
, time
)) {
540 next_f
= sugov_next_freq_shared(sg_cpu
, time
);
542 if (sg_policy
->policy
->fast_switch_enabled
)
543 sugov_fast_switch(sg_policy
, time
, next_f
);
545 sugov_deferred_update(sg_policy
, time
, next_f
);
548 raw_spin_unlock(&sg_policy
->update_lock
);
551 static void sugov_work(struct kthread_work
*work
)
553 struct sugov_policy
*sg_policy
= container_of(work
, struct sugov_policy
, work
);
558 * Hold sg_policy->update_lock shortly to handle the case where:
559 * incase sg_policy->next_freq is read here, and then updated by
560 * sugov_deferred_update() just before work_in_progress is set to false
561 * here, we may miss queueing the new update.
563 * Note: If a work was queued after the update_lock is released,
564 * sugov_work() will just be called again by kthread_work code; and the
565 * request will be proceed before the sugov thread sleeps.
567 raw_spin_lock_irqsave(&sg_policy
->update_lock
, flags
);
568 freq
= sg_policy
->next_freq
;
569 sg_policy
->work_in_progress
= false;
570 raw_spin_unlock_irqrestore(&sg_policy
->update_lock
, flags
);
572 mutex_lock(&sg_policy
->work_lock
);
573 __cpufreq_driver_target(sg_policy
->policy
, freq
, CPUFREQ_RELATION_L
);
574 mutex_unlock(&sg_policy
->work_lock
);
577 static void sugov_irq_work(struct irq_work
*irq_work
)
579 struct sugov_policy
*sg_policy
;
581 sg_policy
= container_of(irq_work
, struct sugov_policy
, irq_work
);
583 kthread_queue_work(&sg_policy
->worker
, &sg_policy
->work
);
586 /************************** sysfs interface ************************/
588 static struct sugov_tunables
*global_tunables
;
589 static DEFINE_MUTEX(global_tunables_lock
);
591 static inline struct sugov_tunables
*to_sugov_tunables(struct gov_attr_set
*attr_set
)
593 return container_of(attr_set
, struct sugov_tunables
, attr_set
);
596 static ssize_t
rate_limit_us_show(struct gov_attr_set
*attr_set
, char *buf
)
598 struct sugov_tunables
*tunables
= to_sugov_tunables(attr_set
);
600 return sprintf(buf
, "%u\n", tunables
->rate_limit_us
);
604 rate_limit_us_store(struct gov_attr_set
*attr_set
, const char *buf
, size_t count
)
606 struct sugov_tunables
*tunables
= to_sugov_tunables(attr_set
);
607 struct sugov_policy
*sg_policy
;
608 unsigned int rate_limit_us
;
610 if (kstrtouint(buf
, 10, &rate_limit_us
))
613 tunables
->rate_limit_us
= rate_limit_us
;
615 list_for_each_entry(sg_policy
, &attr_set
->policy_list
, tunables_hook
)
616 sg_policy
->freq_update_delay_ns
= rate_limit_us
* NSEC_PER_USEC
;
621 static struct governor_attr rate_limit_us
= __ATTR_RW(rate_limit_us
);
623 static struct attribute
*sugov_attrs
[] = {
627 ATTRIBUTE_GROUPS(sugov
);
629 static struct kobj_type sugov_tunables_ktype
= {
630 .default_groups
= sugov_groups
,
631 .sysfs_ops
= &governor_sysfs_ops
,
634 /********************** cpufreq governor interface *********************/
636 struct cpufreq_governor schedutil_gov
;
638 static struct sugov_policy
*sugov_policy_alloc(struct cpufreq_policy
*policy
)
640 struct sugov_policy
*sg_policy
;
642 sg_policy
= kzalloc(sizeof(*sg_policy
), GFP_KERNEL
);
646 sg_policy
->policy
= policy
;
647 raw_spin_lock_init(&sg_policy
->update_lock
);
651 static void sugov_policy_free(struct sugov_policy
*sg_policy
)
656 static int sugov_kthread_create(struct sugov_policy
*sg_policy
)
658 struct task_struct
*thread
;
659 struct sched_attr attr
= {
660 .size
= sizeof(struct sched_attr
),
661 .sched_policy
= SCHED_DEADLINE
,
662 .sched_flags
= SCHED_FLAG_SUGOV
,
666 * Fake (unused) bandwidth; workaround to "fix"
667 * priority inheritance.
669 .sched_runtime
= 1000000,
670 .sched_deadline
= 10000000,
671 .sched_period
= 10000000,
673 struct cpufreq_policy
*policy
= sg_policy
->policy
;
676 /* kthread only required for slow path */
677 if (policy
->fast_switch_enabled
)
680 kthread_init_work(&sg_policy
->work
, sugov_work
);
681 kthread_init_worker(&sg_policy
->worker
);
682 thread
= kthread_create(kthread_worker_fn
, &sg_policy
->worker
,
684 cpumask_first(policy
->related_cpus
));
685 if (IS_ERR(thread
)) {
686 pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread
));
687 return PTR_ERR(thread
);
690 ret
= sched_setattr_nocheck(thread
, &attr
);
692 kthread_stop(thread
);
693 pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__
);
697 sg_policy
->thread
= thread
;
698 kthread_bind_mask(thread
, policy
->related_cpus
);
699 init_irq_work(&sg_policy
->irq_work
, sugov_irq_work
);
700 mutex_init(&sg_policy
->work_lock
);
702 wake_up_process(thread
);
707 static void sugov_kthread_stop(struct sugov_policy
*sg_policy
)
709 /* kthread only required for slow path */
710 if (sg_policy
->policy
->fast_switch_enabled
)
713 kthread_flush_worker(&sg_policy
->worker
);
714 kthread_stop(sg_policy
->thread
);
715 mutex_destroy(&sg_policy
->work_lock
);
718 static struct sugov_tunables
*sugov_tunables_alloc(struct sugov_policy
*sg_policy
)
720 struct sugov_tunables
*tunables
;
722 tunables
= kzalloc(sizeof(*tunables
), GFP_KERNEL
);
724 gov_attr_set_init(&tunables
->attr_set
, &sg_policy
->tunables_hook
);
725 if (!have_governor_per_policy())
726 global_tunables
= tunables
;
731 static void sugov_tunables_free(struct sugov_tunables
*tunables
)
733 if (!have_governor_per_policy())
734 global_tunables
= NULL
;
739 static int sugov_init(struct cpufreq_policy
*policy
)
741 struct sugov_policy
*sg_policy
;
742 struct sugov_tunables
*tunables
;
745 /* State should be equivalent to EXIT */
746 if (policy
->governor_data
)
749 cpufreq_enable_fast_switch(policy
);
751 sg_policy
= sugov_policy_alloc(policy
);
754 goto disable_fast_switch
;
757 ret
= sugov_kthread_create(sg_policy
);
761 mutex_lock(&global_tunables_lock
);
763 if (global_tunables
) {
764 if (WARN_ON(have_governor_per_policy())) {
768 policy
->governor_data
= sg_policy
;
769 sg_policy
->tunables
= global_tunables
;
771 gov_attr_set_get(&global_tunables
->attr_set
, &sg_policy
->tunables_hook
);
775 tunables
= sugov_tunables_alloc(sg_policy
);
781 tunables
->rate_limit_us
= cpufreq_policy_transition_delay_us(policy
);
783 policy
->governor_data
= sg_policy
;
784 sg_policy
->tunables
= tunables
;
786 ret
= kobject_init_and_add(&tunables
->attr_set
.kobj
, &sugov_tunables_ktype
,
787 get_governor_parent_kobj(policy
), "%s",
793 mutex_unlock(&global_tunables_lock
);
797 kobject_put(&tunables
->attr_set
.kobj
);
798 policy
->governor_data
= NULL
;
799 sugov_tunables_free(tunables
);
802 sugov_kthread_stop(sg_policy
);
803 mutex_unlock(&global_tunables_lock
);
806 sugov_policy_free(sg_policy
);
809 cpufreq_disable_fast_switch(policy
);
811 pr_err("initialization failed (error %d)\n", ret
);
815 static void sugov_exit(struct cpufreq_policy
*policy
)
817 struct sugov_policy
*sg_policy
= policy
->governor_data
;
818 struct sugov_tunables
*tunables
= sg_policy
->tunables
;
821 mutex_lock(&global_tunables_lock
);
823 count
= gov_attr_set_put(&tunables
->attr_set
, &sg_policy
->tunables_hook
);
824 policy
->governor_data
= NULL
;
826 sugov_tunables_free(tunables
);
828 mutex_unlock(&global_tunables_lock
);
830 sugov_kthread_stop(sg_policy
);
831 sugov_policy_free(sg_policy
);
832 cpufreq_disable_fast_switch(policy
);
835 static int sugov_start(struct cpufreq_policy
*policy
)
837 struct sugov_policy
*sg_policy
= policy
->governor_data
;
840 sg_policy
->freq_update_delay_ns
= sg_policy
->tunables
->rate_limit_us
* NSEC_PER_USEC
;
841 sg_policy
->last_freq_update_time
= 0;
842 sg_policy
->next_freq
= 0;
843 sg_policy
->work_in_progress
= false;
844 sg_policy
->limits_changed
= false;
845 sg_policy
->need_freq_update
= false;
846 sg_policy
->cached_raw_freq
= 0;
848 for_each_cpu(cpu
, policy
->cpus
) {
849 struct sugov_cpu
*sg_cpu
= &per_cpu(sugov_cpu
, cpu
);
851 memset(sg_cpu
, 0, sizeof(*sg_cpu
));
853 sg_cpu
->sg_policy
= sg_policy
;
856 for_each_cpu(cpu
, policy
->cpus
) {
857 struct sugov_cpu
*sg_cpu
= &per_cpu(sugov_cpu
, cpu
);
859 cpufreq_add_update_util_hook(cpu
, &sg_cpu
->update_util
,
860 policy_is_shared(policy
) ?
861 sugov_update_shared
:
862 sugov_update_single
);
867 static void sugov_stop(struct cpufreq_policy
*policy
)
869 struct sugov_policy
*sg_policy
= policy
->governor_data
;
872 for_each_cpu(cpu
, policy
->cpus
)
873 cpufreq_remove_update_util_hook(cpu
);
877 if (!policy
->fast_switch_enabled
) {
878 irq_work_sync(&sg_policy
->irq_work
);
879 kthread_cancel_work_sync(&sg_policy
->work
);
883 static void sugov_limits(struct cpufreq_policy
*policy
)
885 struct sugov_policy
*sg_policy
= policy
->governor_data
;
887 if (!policy
->fast_switch_enabled
) {
888 mutex_lock(&sg_policy
->work_lock
);
889 cpufreq_policy_apply_limits(policy
);
890 mutex_unlock(&sg_policy
->work_lock
);
893 sg_policy
->limits_changed
= true;
896 struct cpufreq_governor schedutil_gov
= {
898 .owner
= THIS_MODULE
,
899 .dynamic_switching
= true,
902 .start
= sugov_start
,
904 .limits
= sugov_limits
,
907 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
908 struct cpufreq_governor
*cpufreq_default_governor(void)
910 return &schedutil_gov
;
914 static int __init
sugov_register(void)
916 return cpufreq_register_governor(&schedutil_gov
);
918 core_initcall(sugov_register
);
920 #ifdef CONFIG_ENERGY_MODEL
921 extern bool sched_energy_update
;
922 extern struct mutex sched_energy_mutex
;
924 static void rebuild_sd_workfn(struct work_struct
*work
)
926 mutex_lock(&sched_energy_mutex
);
927 sched_energy_update
= true;
928 rebuild_sched_domains();
929 sched_energy_update
= false;
930 mutex_unlock(&sched_energy_mutex
);
932 static DECLARE_WORK(rebuild_sd_work
, rebuild_sd_workfn
);
935 * EAS shouldn't be attempted without sugov, so rebuild the sched_domains
936 * on governor changes to make sure the scheduler knows about it.
938 void sched_cpufreq_governor_change(struct cpufreq_policy
*policy
,
939 struct cpufreq_governor
*old_gov
)
941 if (old_gov
== &schedutil_gov
|| policy
->governor
== &schedutil_gov
) {
943 * When called from the cpufreq_register_driver() path, the
944 * cpu_hotplug_lock is already held, so use a work item to
945 * avoid nested locking in rebuild_sched_domains().
947 schedule_work(&rebuild_sd_work
);